feat(windows): Native AMD ROCm GPU Acceleration (Resolves #531) (#538)

* feat(windows): add native ROCm support for AMD GPUs

Implements native ROCm architecture for Windows.

- Adds backend build pipeline for voicebox-server-rocm.exe

- Detects AMD GPUs dynamically and routes PyTorch allocations

- Adds automatic download and update logic for ROCm dependencies

- Refactors UI in GpuPage.tsx and GpuAcceleration.tsx to add AMD flows

- Fixes 'Switch to CPU' lock on Windows via Tauri backend_override state

- Resolves PyInstaller/rocm_sdk UnboundLocalError silent crashes

- Resolves Numba/NumPy 2.x incompatibilities during Qwen3-TTS load

- Resolves HF_HUB_OFFLINE Catch-22 for CustomVoice processor caching

* fix(rocm): host libs archive under the app release tag, drop offline-load regression

Align the ROCm libs download with the CUDA pattern: both the server core and
the libs archive are published under the app-version release tag, with the libs
content version encoded in the filename only. The previous code fetched libs
from a separate rocm7.2-v1 tag, which disagreed with the download test.

Also revert the unrelated Qwen CustomVoice changes that wrapped model loading in
force_offline_if_cached (not imported — a NameError on load for every platform)
and re-added a Base-model cache gate. The inference-path offline guard was
deliberately removed previously.

* feat(rocm): gate download on AMD detection and persist the backend variant

The ROCm download section now only shows when the backend reports an AMD GPU on
Windows (new supports_rocm health field, backed by the memoized
is_amd_gpu_windows detection that was previously unused), or when ROCm is already
downloaded/active.

Make the backend override honor a pinned variant: set_backend_override persists
the choice to disk so it survives an app restart, start_server reads it back,
and a cuda/rocm pin now actually selects that variant instead of always
preferring ROCm. A stale pin to a deleted backend self-heals to the default
order rather than forcing CPU. Add the web no-op stub for the new method.

* chore(rocm): drop incomplete vitest harness for the unused GpuAcceleration component

GpuAcceleration.tsx is not routed anywhere (GpuPage is the live settings view),
and the added vitest setup referenced testing-library/vitest deps that were not
in the lockfile, breaking the web typecheck. Remove the dead component's test
and its scaffolding to keep this PR scoped to the ROCm feature.

* ci(rocm): add ROCm release-artifact pipeline

Mirror the CUDA packaging path for ROCm so the runtime download has artifacts to
fetch. scripts/package_rocm.py splits the PyInstaller --rocm onedir into
voicebox-server-rocm.tar.gz (core) + rocm-libs-rocm7.2-v1.tar.gz (AMD runtime:
HIP DLLs, rocBLAS Tensile data, MIOpen kernel DBs) + rocm-libs.json, matching
the names services/rocm.py expects, both under the app-version release tag.

The new build-rocm-windows job in release.yml builds on windows-latest/cp312 and
lets build_binary.py --rocm pull the official AMD Radeon wheels.

The file classifier can't be validated against a real AMD build on CI, so it has
unit coverage (test_package_rocm.py) against a synthetic onedir layout. The
prefixes/dir markers may need a tweak after the first real build on AMD
hardware — the packager hard-fails loudly if it classifies zero ROCm files.

---------

Co-authored-by: Jamie Pine <[email protected]>

app/src/i18n/locales/en/translation.json

@@ -760,8 +760,13 @@
       }
     },
     "general": {
-      "docs": { "title": "Read the Docs" },
-      "discord": { "title": "Join the Discord", "subtitle": "Get help & share voices" },
+      "docs": {
+        "title": "Read the Docs"
+      },
+      "discord": {
+        "title": "Join the Discord",
+        "subtitle": "Get help & share voices"
+      },
       "serverUrl": {
         "title": "Server URL",
         "description": "The address of your voicebox backend server.",
@@ -1091,11 +1096,15 @@
       "active": "Active",
       "cuda": {
         "title": "CUDA Backend",
+        "activeTitle": "CUDA Backend Active",
         "description": "NVIDIA GPU acceleration via a downloadable CUDA backend.",
         "downloading": "Downloading CUDA backend…",
         "downloadingShort": "Downloading…",
         "updating": "Updating…"
       },
+      "activeBackend": {
+        "description": "GPU acceleration is currently enabled."
+      },
       "restart": {
         "ready": "Server restarted successfully",
         "waiting": "Restarting server…",
@@ -1113,10 +1122,9 @@
       },
       "switchToCpu": {
         "title": "Switch to CPU backend",
-        "description": "Disable GPU acceleration. You can re-download CUDA later.",
+        "description": "Disable GPU acceleration. You can re-download the GPU backend later.",
         "button": "Switch"
-      },
-      "remove": {
+      },      "remove": {
         "title": "Remove CUDA backend",
         "description": "Delete the downloaded CUDA binary to free disk space.",
         "button": "Remove"
@@ -1126,9 +1134,33 @@
         "downloadStart": "Failed to start download",
         "restartFailed": "Restart failed",
         "switchCpu": "Failed to switch to CPU",
-        "deleteCuda": "Failed to delete CUDA backend"
+        "deleteCuda": "Failed to delete CUDA backend",
+        "deleteRocm": "Failed to delete ROCm backend"
       },
-      "footer": "Voicebox automatically detects and uses the best available GPU on your system. On Apple Silicon Macs, the MLX backend runs natively on the Neural Engine and GPU via Metal Performance Shaders (MPS), with no additional setup required. On Windows and Linux with NVIDIA GPUs, you can download an optional CUDA backend for hardware-accelerated inference. AMD ROCm, Intel XPU, and DirectML are also supported where available through PyTorch. When no GPU is detected, Voicebox falls back to CPU — all engines still work, just slower."
+      "footer": "Voicebox automatically detects and uses the best available GPU on your system. On Apple Silicon Macs, the MLX backend runs natively on the Neural Engine and GPU via Metal Performance Shaders (MPS), with no additional setup required. On Windows, you can download optional CUDA (NVIDIA) or ROCm (AMD) backends for hardware-accelerated inference. Intel XPU and DirectML are also supported where available through PyTorch. When no GPU is detected, Voicebox falls back to CPU — all engines still work, just slower.",
+      "rocm": {
+        "title": "AMD ROCm Backend",
+        "activeTitle": "ROCm Backend Active",
+        "description": "AMD GPU acceleration via a downloadable ROCm backend.",
+        "downloading": "Downloading ROCm backend…",
+        "downloadingShort": "Downloading…",
+        "updating": "Updating…"
+      },
+      "downloadRocm": {
+        "title": "Download AMD ROCm backend",
+        "description": "~2-3 GB download. Requires an AMD Radeon GPU with ROCm support.",
+        "button": "Download"
+      },
+      "switchToRocm": {
+        "title": "Switch to ROCm backend",
+        "description": "ROCm backend is downloaded and ready. Restart to enable.",
+        "button": "Restart"
+      },
+      "removeRocm": {
+        "title": "Remove ROCm backend",
+        "description": "Delete the downloaded ROCm binary to free disk space.",
+        "button": "Remove"
+      }
     },
     "logs": {
       "title": "Server Logs",